any ideas what can cause an angel to hide out for a day? its been in a spot that i cant see, and every once in a while it swims by a hole so i get a glance, its been doing great for a couple months, nothing is in there to hurt it, fish or corals. i just moved my tank, nothing is bleaching, nothing is dying, i dropped my fuge, but i dont think nitrates would effect him. any ideas? its a cherub BTW, any chance it could be a female that laid eggs and is just protecting them? i cant get a good enough look to see if its sick or anything, but from what i saw, it seems fine. just hiding.